New Spanish GAAP based on IFRS came into force for separate financial statements in 2008. Companies were allowed to choose between 1 January 2007 and 1 January 2008 as their transition date. The first option commits companies to presenting comparative statements while the second allows them to disclose only the adjustments in equity. We analyze the determinants of companies that decided to choose early transition and also the consequences of this choice on the main accounting figures and ratios. Our results show that the determinants of the early transition date are size and growth. As for the consequences, there is a significant change in the accounting figures and ratios and therefore comparability may be impaired. © 2012 Copyright European Accounting Association.